Grinding machine



Jan. 20, 1942.

A. S. JOHNSON GRINDING MACHINE l Filed Jan. ll, 1959 4 Sheets-Sheet l WM5/V727@ a LW ,m Z/

Jan. 2o, '1942.'

A. S. -JOHNSON GRINDING MACHINE Filed Jn. ll, 1939 l 4 Sheets-Sheet 2 Jan. 20, 1942. A. s. JOHNSON GRINDING MACHINE 4 Sheets-Sheet 3 Filed Jan.

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'Ian. 20,1942. A. s. JOHNSON I 2,270,446 v GRINDING MACHINE Filed Jan. ll, 1939 4 Sheets-Sheet 4 GRINDING A WHEEL. v BRUSH `AlooomaaFaM- Ly 35o RPM.

`Patented Jan. 2G, 1942 UNITED STATES PAT lzfrnfA y OFFICE Arthur S.. Josllca, assigner to- United Shoe Machinery Corporation, Borough of Flemington, N. J., a` corporation` of' New Jersey Applicationaanuary 11, 1939,` seriarNo; .einemi (or. fsa-1) lzClaims.

This invention relates, generally, to al method of and device for grinding rotary tools and especially those having roughing elements, such as Wire bristles, for roughing the surface of leather or` other material preparatory to the application of adhesive cement. More particularly, it has, for its purpose, the sharpening and maintenance of the proper shape of the peripheral contour of a roughing tool made of wire bristles especially shaped for roughing the channel flap and channel base of a channelled sole preparatory to. cementing the channel so that the channel flap can be laid down and secured in its original position to conceal the seam by which the` outsole issecured to a shoe.

When a rotary" roughing tool consisting of a Wire bristle brush is used for roughing leather or similar material, the ends of the bristles must be kept sharp andthe brushes are more eiiicient for this purpose if the ends of the wire bristles have burrs on their leading` edge similar `to. the burr on a cabinet-makers scraper and When the ends also have a clearance angle behind the leadi'n'g edges. Such an angle is produced when the radial length of the following side of eachbristle is shorter than that of the leading side. The difference in length is minute, of course.in the small sizes of bristles` used for this Work.

In order to produce the roughing burr on the leading edge of each bristle end, it is necessary for the abrasive particles in the grinding device to pass across the ends ofv the bristles from rear to front, so that'the particles `oi abrasive leave contact With each bristle at the leading edge thereof. i

In order to provide the suitable clearancel angle on the ends of the bristles, so that the following edge Will not ride upon the Work and preventthe leadingv edge from roughing` the work, itis. necessary,v While the grindingis being performed, toV deflect each bristle forwardly or toward its lead'- ing edge. This deflection naturally occurs from the frictional contact of the abrasive as itA acts on the end of each bristle as the particles move from rear to front or in the rsame manner that they move in producing the burr. It should be noted that the bristles, when in use, become dulled on their leading edges,I dueto the fact that the bristles are circumferentially deflected in the opposite direction, ,orA rearwardly, byl contact with the Work that is being rcughed..

Heretofore, in order to obtain this burr and` clearance angle, it has been necessary, when .thel brush is being sharpened; to rotate it in'. the opduring a ro'ughing'l operation. In order' to do this" ithas beennecessary, eitherto" remove"` the brush from the machine in which it is used and mount it in a grinding device Where it may be rotated in a reverse direction, or' else it' has been necessary to arrange a4 reverse drive for the brush in the roughing' machine Aitself There arev obvious objections to both of these methods ofv procedure. In the first instance, considerable time is wasted by the operator in removing the brush from the machine where it ist us'ed and then remoun'ting it in a jig or fixture in a position so that it may b'e rotated in the reversed direction to be sharpened. In the second instance, it is necessary to complicate the machine by adding a reverse drive mechanism in order to reverse the normali` direction of rotation of the brush for the sharpeningl operation.

-It is `an object of the present invention to over` come the above objections and provide a grinding device which may be permanently mounted onv the roughing machine and Which, When necessary; may b'e positioned in contact With the roughing tool While it is rotating as in thenormal operation of the machine, i. e., to grind the produce and;` maintain the desired peripheral contour on the tool for the Work at hand. In.

this' arrangenrent,y in order to produce the desider burr and clearance angle, the grinding: Wheel is arranged. to rotate so that the part' of its periphery that is.` in contact with the brush moves in the same directionv as the movement of' the contacting surface of the brush', but at a` much higher speed, so that the abrading particles onthe Wheel, afterpassing across the-ends of the bristles. aty high` speed,4 leave` such ends at theirA leading edge, producing: a burr which will be the iirst part of each lo'ristleto'*strikeI thework in the` roughing' operation. It is obvious that thisfarran'gement also producesthe desired cleariance angle behind the leading edge of each bristle.

M In Lother Words,A the` grinding WheelV is arranged to rotate at a relatively high peripheral speed positfe direction from that in which it rotates 55 Whilerthe brush is rotating in its usual location and in its normal direction at a substantially slower speed, with the contacting surfaces of both moving in the same direction.

It is, of course, unnecessary for the grinding wheel to be in rotation when the rotary tool is being used. In order to simplify the operation of the device and to prevent waste of power and possible injury because of carelessness on the part of the operator in neglecting to shut off the power to the grinding wheel after a tool or brush has been sharpened, another feature of the construction consists in automatic means for stopping the grinding wheel when it is moved into inoperative position. In the preferred construction, the wheel is rotated by means of an electric motor and, as illustrated, provision is made whereby the swinging of the wheel into inoperative position moves to the olf position the switch which controls the current that is supplied to the motor. As an alternative, a pneumatic or other fluid motor may be substituted for the electric motor.

It is within the scope of the invention to mount the grinding wheel so as to sharpen some other form of rotating tool, such as a circular knife. Means for shutting 01T the power from the grinding wheel when it is swung into inoperative position may also be provided with such modied construction.

The invention will be better understood when the following specication is considered in connection with the accompanying drawings, in which Fig. 1 is a front elevation of a portion of a channel-roughing machine, showing the grinding attachment of the present invention mounted thereon, with the grinding wheel swung into an angular position for grinding an angular face of a roughing brush;

Fig. 2 is a similar View on a larger scale, showing further details of the grinding attachment, with the grinding wheel swung into position preparatory to feeding it across the face of a cylindrical roughing brush; Fig. 3 is an end View of a roughing machine and the grinding attachment, with the grinding wheel slightly separated from the roughing brush and with kthe shaft of the grinding wheel in parallel relation to the brush shaft for grinding a cylindrical surface on the brush, i. e., as shown in Fig. 2;

Figs. 4 and 5 are details of construction of the guard for the grinding wheel;

Fig. 6 is a perspective view of the attachment with the grinding wheel swung into and locked in inoperative position;

Fig. 7 is a plan View of further details of construction;

Figs. 8 to 13, inclusive, show two different combinations of two-part roughing brushes, and the location in which the grinding wheel should be positioned to true up and sharpen these different shapes;

Fig. 14 is an enlarged View of one ofthe wire bristles of which the roughing brush is composed and shows the burr produced on its end by the grinding operation; and

Fig. 15 is a diagrammatic view showing the directions of rotation of the brush and grinding wheel, and their relative peripheral speeds, whereby the proper roughing burrs and clearance angles are produced on the ends of the bristles of the brush. y

The frame of a channel-roughing machine is shown at 2|) and from this frame projects a rotatable shaft 22 on which is mounted a two-part roughing brush. The part 24 of the brush operates on the channel base and the part 26 operates on the channel lip, to roughen these parts of a channeled sole of a shoe, preparatory to a cementing operation. An adjustable guide 28 is provided for guiding the shoe during the channel roughing operation. Such a channel roughing machine is shown in the copending application for United States Letters Patent Serial No. 125,608, led February 13, 1937, in the name of Arthur S. Johnson, since issued as Patent No. 2,179,507, granted November 14, 1939.

In order that the grinding attachment may be conveniently located for truing up and sharpening the roughing brush, the attachment is mounted on a xed bracket 30, which bracket is secured to a fixed rod 32 that also carries a portion of the roughing machine. The rod 32 extends horizontally from the frame 29 and passes through a hole in the bracket 38. The bracket 30 is secured to the rod 32 by set screws (not shown) after being positioned rotatively by an adjusting screw 34, which bears against the frame 20.

The fixed bracket 3U is provided with a vertical pivot pin 36, which is held in position by a set screw 37. On the pin 36 is pivoted a swinging bracket 38. The fixed bracket 30 is provided with an overhanging arm 40, having a tapped hole through which a knurl-headed locking screw 42 is threaded. The lower conical end of the screw 42 may pass into either one of two countersunk holes 44 or 45 in the swinging bracket 38, to lock the bracket, respectively, in either operative or inoperative position, as will be made clear later. The bracket 38 has a vertical bearing for a pivot pin 46 which is secured in a second swinging bracket 50 by a set screw 5|. The bracket 50 may be swung into any definite angular position, as indicated by a graduated scale 52 and an index mark 54, and locked in the desired positionby a clamping screw 56 which is tapped into the bracket 50 and passes through an arcuate slot 58 in the bracket 38. (See Fig. '7.)

Depending from the swinging bracket 50 are two separated ears 6U and 62 having bearings between which is mounted a shaft 64 having a coarse feed screw 66 cut thereon. `'Ihe shaft 64 1s prevented from longitudinal movement between the bearings by a collar 68 on one end and a crank HJ on the other end, the latter being provided with a handle '|2 by which the screw 66 may be rotated. A depending bracket hangs from the feed screw 66 and can be fed thereby across the roughing tool. An electric motor is mounted on the under side of the bracket 80 and carries a grinding wheel 92 mounted on a laeeve secured to the motor shaft by a set screw In order to swing the motor and its grinding wheel about the feed screw 66 into a desired adjusted position, an adjusting screw 94 is arranged to turn freely in a bracket 96 which is carried on the top of the threads of the feed screw 66 between ears 97, 98 of the bracket 88. In order -to prevent the bracket 96 from turning about the axis of the feed screw 66, the bracketV is provided with a lug |80 and a cooperating gib |92 which' bear on' opposite sides of a guideway |84 that is integral with, and depends from, the bracket 50. Ihe shank |06 of the adjusting screw 94 is tapped into a short shaft |08 which is freely mounted in the bracket 80 and provides a Iswivel connectionl betweensitand'the bracket $16-,v whcrebyiturning theadjust'ingscrew 94A willi move ther. motor and'. grinding` wheeh 822 aboutthe-feed. screwl 66 tow-ard and from. theiroughing tool. Interposed between. the bracket' 96 and the;I short shaft |08 is a stiff spring I to take up backlashwhile permitting az. micrometric. adjustment. of the; grinding.-v wheel'.toward:` and. fromi the; roughingi tool. Witlrthis arrangement, only a. limitedamount of materiali will be, ground off.vv at; aatime and.V overloading.' o ff the; motor'isprevented..

It: will. be seenv that; with; th'e.` above` construction;V the'y grinding.v wheel. 921 mayI be.- located. and securediinthe several positionsf'sh'own.' in Figs. 8 to i 13;. inclusive, and fed. across 'the brush. by the 'crankhandle 7.2: an'd'madefto assume-1 any adjustedi position toward. and: fromgthe. brush. bysthe adjusting. screw 941i toA determinetthe amount: of

material ground off from=the roughing brush.

Thegrinding'wheel 921s providedwith a.. guard |28? to'. protect:A the operator from` flying dus-t` and possible; breakage of. the grinding. wheel. This guard islsomounted that itxpartakesgof the positioning movements of the grinding wheel and motor. The mounting consistsv ofa rod |22.v secured;..by ai setscrew |24, to the swinging bracket 601 that: carriessthe motor. Adjustably.` mounted onitheu rod: |22y isa clamp member |26 held in adjusted. position by: ayclamp screw |28.. The guarda. |26 is pivotally mounted: on therear portion; ofz the:- clamp I 26. l by means. of a. shouldered pivotiscrew |29 movingwith theguard, thescrew havingzthefend of itsshoulder |30 seated securely cna threaded washer |132 fastened to the guard by means of a rivet |34. The guard |20, and its attached.` pivot. screw |28, may be turned about the axis of the screw |28, the screw turning in a hole in the clamp |26. The guard will be held in any adjusted position by a spring pressed ball |36 acting against teeth |38, formed on the shouldered y part of the screw. (See Figs. 4 and 5.)

The manner in which the directions of rotation of the brush and grinding wh'eel, and their relative peripheral speeds, form a burr on the leading edge on the end of each of the bristles of the roughing brush, with a clearance angle behind each leading edge, will be clear from an inspection of the diagrammatic view of Fig. 15.

In order to assure that the current is shut oi from the grinding attachment when it is swung into inoperative position, automatic means are provided for the purpose. I After the locking screw 42 has been freed from the counter-sunk hole 44, the bracket 38 is swung about its pivot 36 into inoperative position (see Fig. 6), at which time va flat-faced lug |50, integral with the bracket 38, strikes an arm |52 of a pivoted double-armed lever |54 and turns it. As the lever turns, its other arm |56 strikes the handle |58 of a toggle switch mounted in a box |60 and turns it to the foifposition This severs the electrical connection between a portable cord |62 leading from the source of electric power and an armored cable |64 extending from the box |60 to the motor 90. The bracket is then locked in inoperative position by' turning the locking screw 42 into the countersunk hole 45. The switch cannot be thrown to the on position until after the operator has swung the attachment into operating between the handle |58 and the arm |56 of the lever, Accordingly, the motor may be stopped at any time. ty.y throwing tne'switch handle. usato the.off. position.. but it cannot bethro'wnr. tol the onfv position while the grinding attachment. is

ini inoperative position.` y

brusnand with the contactingA portions off` the brush-and the grinding. wheel moving inthe same] direction; y

2. The method ofi grinding theroughing ele- `ments' of arotary' roughing tool-which consistsfin rotating` the tooly in its usualV operating i direction and in its" usual" operating position and inrota'tingu a grinding wheel in grinding contact with' t the outer ends of theV elements to grind them While-the elementsare circumferentially deectcd forwardly, so-as4 to produce a clearance anglecn theclends of *said elements.

3^. The method of grinding the4 bristles ofz a wire brush which consists in rotating a brushin situ in a roughing machine in itsusualfoperating direction and in rotating a grindingv Wheel" in contact with the ends'of the bristleslof-thebrush with a greater peripheral speed' thazrthat of the brushl andfwith the contacting portions ofthe brush and the-grinding wheel moving in thesarn'e direction.`

4. The method of grinding the roughing*-'ele-` ments of a rotary roughing tool which-consists in' rotating a toolin its usual operating direction while mounted in a roughing machine in its usual operating position and in rotating a grinding wheel in grinding Contact with the outer ends of the roughing elements to grind them While the elements are circumferentially deflected forwardly, so as to produce a clearance angle on the ends of said elements.

5. The method of grinding the wire bristles of a rotary roughing brush which consists in rotatl in a roughing machine and in `rotating a grinding wheel in grinding contact with the outer ends of ,the bristles with the contacting surface of the Wheel moving in the same direction as, and much v faster than, the ends of the bristles.

7. A machine having, in combination, a rotary brush provided with wire roughing bristles, means for rotating the brush, a grinding wheel, and

' means arranged to lrotate said wheel at a peripheral speed greater than that of the brush and with the contacting portions of the brush and the wheel moving in the same direction.

8. A machine having, in combination, a rotary brush provided with wire roughing bristles, means for rotating the brush in a given direction and at. a certain speed to perform a roughing operation upon a piece of work, a grinding wheel mounted in inoperative position, means for moving the Wheel into operative position to sharpen the bristles while the brush is rotating in said direction and at said speed and `not performing a roughing operation, and means for rotating the grinding wheel at a peripheral speed greater than the peripheral speed of the brush and with the contacting portions ofthe brush and the wheel moving in the same direction, to produce a roughing burr on the leading edge of each bristle.

9.- A machine for roughing shoe parts having, in combination, a rotary tool provided with a multitude of flexible roughing elements extending outwardly to its circumference, said elements being circumferentially deilected rearwardly by contact with shoe parts Whenthe tool is rotated in its normal direction to use the outerl ends of the elements for roughing purposes, means for rotating the tool in saidv direction, a grinding Wheel, means to position said wheel in grinding contact with the roughing elements of said tool while the tool is rotating in its normal direction and means arranged to rotate said wheel at a peripheral speed greater than that of the tool and with the contacting portions of the tool and the wheel moving in the same direction, so that the rotating wheel will deiiect the rotating roughing elements circumferentially forwardly and grind them in situ `with a clearance angle on the ends of Said elements.

'10. A machine for roughing shoe parts having,

in combination, a rotary tool provided with a multitude of exible roughing elements extending outwardly to its circumference, means rotating said tool, a grinding wheel, means rotating said wheel at a higher peripheral speed than the tool, and means to position the rotating Wheel in grinding contact with the roughing elements of said tool while the tool is rotating in its normal direction, so that the rotating Wheel will grind the rotating roughing elements in situ with a roughing burr on the leading edge of the ends of said elements.

11. A device for grinding the roughing bristles of a rotary roughing tool in situ, having, in combination, a series of pivotally connected brackets, a grinding Wheel mounted to move with the last bracket of the series, means for moving said last bracket in two directions at right angles to each other to feed the Wheel bothV toward and across the tool, means for locking the remaining brackets of the series in either angularly adjusted operating position or in inoperative position, and means for rotating the grinding wheel at a speed and in the direction to produce a roughing burr on the leading edge of the bristle ends.

12. A device for grinding the roughing elements of a rotary roughing tool in situ, having, in combination, a series of pivotally connected brackets, a grinding wheel mounted to move with the last bracket of the series, means for moving said last bracket in two directions at right angles to each other to feed the wheel both toward and across the tool, meansfor locking the remaining brackets of the series in either angularly adjusted operating position or in inoperative position, and an electric motor for rotating the grinding wheel in such a direction and at such a speed that the contacting surfaces of the Wheel and tool move in the same direction, with the surface of the wheel moving much faster than the surface of the tool.

ARTHUR S. JOHNSON. 

